Bucking a tide of resistance in state capitals and a free-spirited breed of motorcyclists, the National Transportation Safety Board on Tuesday said states should require riders to wear federally approved helmets.

The recommendation comes after a five-year trend of steadily rising motorcycle deaths was reversed in 2009, when 4,462 riders died in crashes. The most recent data, from 2008, indicated that 65 percent of motorcyclists killed were not wearing helmets.

"Too many lives are lost in motorcycle accidents," Christopher A. Hart, NTSB vice chairman, said in announcing that helmets had been added to the board's annual "most-wanted list" of safety improvements. "It's a public health issue."

The NTSB uses the list as part of its bully pulpit on safety issues since the power to regulate lies with Congress, other federal agencies and state legislatures.

In 1967, Congress threatened to withhold highway funding for states that failed to adopt universal helmet requirements for motorcyclists. But after nine years of lobbying by motorcycle groups, Congress returned the decision-making power to the states. In 2005, it prohibited states from using federal money to promote helmet use.

Since 1976, many states have scaled back or abandoned helmet requirements. Only 21 jurisdictions - including Virginia, Maryland and the District - still require all riders and passengers to wear helmets. Twenty-seven other states require only passengers or children to wear helmets. Three states - Illinois, Iowa and New Hampshire - have no helmet requirement.

Several other items are also on the NTSB's most wanted list.

The board said it would continue to push states to strengthen licensing requirements for young drivers. Though 49 states and the District have moved toward graduated licensing systems, only 15 states have complied with all of the NTSB's recommendations.

The NTSB also will continue its advocacy for use of booster seats by young children, saying that about 45 percent of the 3,000 children between the ages of 4 and 8 who died in motor vehicle accidents between 2000 and 2009 were unrestrained.

The board will encourage all states to enact primary seat-belt enforcement laws. Nineteen states, including Virginia, still require police to have another reason for stopping a vehicle before a seat-belt ticket can be issued.

Citing data that showed "hard-core drinkers" were responsible for accidents that killed 7,607 people in 2009, the board said it would press states to make more use of sobriety checkpoints and interlock devices that prevent those with a record of drunk driving from starting their vehicle while intoxicated.

"Last year, more than 33,000 people died in highway crashes," NTSB Chairman Deborah A.P. Hersman said. "That's the equivalent of losing five 737 passenger jets every week. . . . It's time for states that lag behind to step up and put in place the safety measures we've highlighted today."